A diet high in fats and low in fiber increases the risk of cancer.
A diet with plenty of fresh fruits and vegetables decreases the risk of cancer.
Smoked foods, especially smoked meats, increase the risk of cancer.
Tobacco, smoked or chewed, is the single highest risk factor for cancer.
Regular exercise decreases the risk of cancer.
Avoid x-rays and CT scans unless necessary as radiation increases the risk of cancer.
Avoid direct contact with chemicals.

Those with a family history of cancer
Chronic and long term users of tobacco: smokers and pan chewers
Regular consumers of alcohol
Those exposed to chemicals or radiation at work
Those infected by viruses such as Hepatitis B and HPV (Human Papilloma Virus)